Add emoji checks, improve docs

README.md

@@ -33,6 +33,13 @@ stdout (or "None" if it cannot determine anything).
 
 This will print the compiled model in JSON to stdout.
 
+### Packing models
+
+    gptc pack <dir>
+
+This will print the raw model in JSON to stdout. See `models/unpacked/` for an
+example of the format. Any exceptions will be printed to stderr.
+
 ## Library
 
 ### `gptc.Classifier(model, max_ngram_length=1)`
@@ -52,12 +59,44 @@ category:probability, ...}`
 Classify `text`. Returns the category into which the text is placed (as a
 string), or `None` when it cannot classify the text.
 
+#### `Classifier.model`
+
+The classifier's model.
+
+#### `Classifier.has_emoji`
+
+Check whether emojis are supported by the `Classifier`. (See section "Emoji.")
+Equivalent to `gptc.has_emoji and gptc.model_has_emoji(model)`.
+
 ### `gptc.compile(raw_model, max_ngram_length=1)`
+
 Compile a raw model (as a list, not JSON) and return the compiled model (as a
 dict).
 
 For information about `max_ngram_length`, see section "Ngrams."
 
+### `gptc.pack(directory, print_exceptions=False)
+
+Pack the model in `directory` and return a tuple of the format:
+
+    (raw_model, [(exception,),(exception,)...])
+
+Note that the exceptions are contained in single-item tuples. This is to allow
+more information to be provided without breaking the API in future versions of
+GPTC.
+
+See `models/unpacked/` for an example of the format.
+
+### `gptc.has_emoji`
+
+`True` if the `emoji` package is installed (see section "Emoji"), `False`
+otherwise.
+
+### `gptc.model_has_emoji(compiled_model)`
+
+Returns `True` if `compiled_model` was compiled with emoji support, `False`
+otherwise.
+
 ## Ngrams
 
 GPTC optionally supports using ngrams to improve classification accuracy. They
@@ -84,6 +123,10 @@ If the [`emoji`](https://pypi.org/project/emoji/) package is installed, GPTC
 will automatically handle emojis the same way as words. If it is not installed,
 GPTC will still work but will ignore emojis.
 
+`emoji` must be installed on both the system used to compile the model and the
+system used to classify text. Emojis are ignored if it is missing on either
+system.
+
 ## Model format
 
 This section explains the raw model format, which is how you should create and

gptc/__init__.py

@@ -5,6 +5,8 @@
 from gptc.compiler import compile as compile
 from gptc.classifier import Classifier as Classifier
 from gptc.pack import pack as pack
+from gptc.tokenizer import has_emoji as has_emoji
+from gptc.model_info import model_has_emoji as model_has_emoji
 from gptc.exceptions import (
     GPTCError as GPTCError,
     ModelError as ModelError,

gptc/classifier.py

@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: LGPL-3.0-or-later
 
-import gptc.tokenizer, gptc.compiler, gptc.exceptions, gptc.weighting
+import gptc.tokenizer, gptc.compiler, gptc.exceptions, gptc.weighting, gptc.model_info
 import warnings
 from typing import Dict, Union, cast, List
 
@@ -33,6 +33,7 @@ class Classifier:
         self.model = model
         model_ngrams = cast(int, model.get("__ngrams__", 1))
         self.max_ngram_length = min(max_ngram_length, model_ngrams)
+        self.has_emoji = gptc.tokenizer.has_emoji and gptc.model_info.model_has_emoji(model)
 
     def confidence(self, text: str) -> Dict[str, float]:
         """Classify text with confidence.

gptc/model_info.py

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: LGPL-3.0-or-later
+
+import gptc.compiler
+from typing import Dict, Union, cast, List
+
+
+def model_has_emoji(model: gptc.compiler.MODEL) -> bool:
+    return cast(int, model.get("__emoji__]", 0)) == 1